/**
 * Copyright 2011-2013 FoundationDB, LLC
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* The original from which this derives bore the following: */

/*

   Derby - Class org.apache.derby.impl.sql.compile.AggregateNode

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to you under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package com.bj58.sql.parser;

import com.bj58.sql.StandardException;

/**
 * An Aggregate Node is a node that reprsents a set function/aggregate.
 * It used for all system aggregates as well as user defined aggregates.
 *
 */

public class AggregateNode extends UnaryOperatorNode
{
    private String aggregateName;
    private String aggregateDefinitionClassName;
    private boolean distinct;

    /**
     * Intializer.  Used for user defined and internally defined aggregates.
     * Called when binding a StaticMethodNode that we realize is an aggregate.
     *
     * @param operand   the value expression for the aggregate
     * @param uadClass  the class name for user aggregate definition for the aggregate
     *                  or internal aggregate type.
     * @param distinct  boolean indicating whether this is distinct
     *                  or not.
     * @param aggregateName the name of the aggregate from the user's perspective,
     *                      e.g. MAX
     *
     * @exception StandardException on error
     */
    public void init(Object operand,
                     Object uadClass,
                     Object distinct,
                     Object aggregateName) 
            throws StandardException {
        super.init(operand);
        this.aggregateDefinitionClassName = (String)uadClass;
        this.aggregateName = (String)aggregateName;
        this.distinct = ((Boolean)distinct).booleanValue();
    }

    /**
     * Fill this node with a deep copy of the given node.
     */
    public void copyFrom(QueryTreeNode node) throws StandardException {
        super.copyFrom(node);

        AggregateNode other = (AggregateNode)node;
        this.aggregateDefinitionClassName = other.aggregateDefinitionClassName;
        this.aggregateName = other.aggregateName;
        this.distinct = other.distinct;
    }

    /**
     * Get the name of the aggregate.
     *
     * @return the aggregate name
     */
    public String getAggregateName() {
        return aggregateName;
    }

    /**
     * Indicate whether this aggregate is distinct or not.
     *
     * @return true/false
     */
    public boolean isDistinct() {
        return distinct;
    }

    /**
     * Convert this object to a String.  See comments in QueryTreeNode.java
     * for how this should be done for tree printing.
     *
     * @return This object as a String
     */

    public String toString() {
        return "aggregateName: " + aggregateName + "\n" +
            super.toString();
    }

}
